We propose to develop a new technique for delivering iron chelators to critical organs in order to increase the efficacy for iron removal. This technique involves a biological carrier, called a "liposome." The foundation of this approach is Cell Biology, particularly in the areas of: membrane chemistry, membrane movement, and cellular enzymology. The main objectives of this proposal are the following: 1. To protect the iron chelator -- desferrioxamine (DF) by liposome encapsulation, from enzymatic degradation in the animal circulation. 2. To prevent rapid excretion of DF from the animal body. 3. To direct the DF to critical organs of iron storage, by encapsulation of DF within liposomes varying in surface properties. 4. To reduce the toxic side effects of DF to mice. 5. To increase the therapeutic index of DF to experimental iron overloaded mice.